Information Hiding—A Survey
- page 13 / 17

ple, when monitoring radio transmissions to ensure that adverts have been played as contracted, we only require enough resistance to distortion to deal with naturally oc- curring effects and prevent transfer of marks from one ad- vert to another [140]; and where our concern is to make proprietary images available to scholars, as in the ‘Vati- can Library Accessible Worldwide’ project, IBM came up with a simple solution using visible watermarks – which leave the the documents still perfectly suitable for research purposes but discourage illegal publication for profit [12].

[3]

[4]

[5]

[6]

VI. Conclusion

In this paper we gave an overview of information hid- ing in general and steganography in particular. We looked at a range of applications and tried to place the various techniques in historical context in order to elucidate the relationships between them, as many recently proposed sys- tems have failed to learn from historical experience.

[7]

[8]

[9]

We then described a number of attacks on information hiding systems, which between them demolish most of the current contenders in the copyright marking business. We have described a tool, StirMark, which breaks many of them by adding sub-perceptual distortion; and we have described a custom attack on echo hiding.

[10]

[11]

[12]

This led us to a discussion of marking in general. We de- scribed some of the problems in constructing a general the- ory and the practical requirements that marking schemes and steganographic systems may have to meet. We ad- vanced the suggestion that it is impractical to demand that any one marking scheme satisfy all of these require- ments simultaneously; that is, that ‘the marking problem,’ as sometimes described in the literature, is over-specified.

[13]

[14]

[15]

That does not of course mean that particular marking problems are insoluble. Both historical precedent and re- cent innovation provide us with a wide range of tools, which if applied intelligently should be sufficient to solve most of the problems that we meet in practice.

[16]

[17]

[18]

Acknowledgements

[19]

Some of the ideas presented here were clarified by discus- sion with Roger Needham, John Daugman, Peter Rayner, Martin Kutter and Scott Craver. The first author is grate- ful to Intel Corporation for financial support under the grant ‘Robustness of Information Hiding Systems’ while the third author is supported by the European Commission under a Marie Curie training grant. Special thanks to the Whipple Science Museum Library, the Rare Book Section of the Cambridge University Library, and the Cambridge University Archives, for their help.

[20]

[21]

[22]

[1]

A. Tacticus, How to survive under siege / Aineias the Tac- tician, pp. 84–90, 183–193. Clarendon ancient history series, Oxford, England: Clarendon Press, 1990, ISBN 0-19-814744-9, translated with introduction and commentary by David White- head. J. Wilkins, Mercury: or the secret and swift messenger: shew- ing, how a man may with privacy and speed communicate his thoughts to a friend at any distance. London: printed for Rich